简单的 同步 异步 请求

 #import "ViewController.h"


@interface ViewController ()

@property(nonatomic,strong)UITextView *textView;
@property(nonatomic,copy)NSString *BASE_URL;
@property(nonatomic,copy)NSString *BASE_URL1_PARAM;
@property(nonatomic,strong)NSMutableData *mutableData;

@end


@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

}

#pragma mark - get同步

- (IBAction)getSyncButtonAction:(UIButton *)sender

{

    NSString * BASE_URL= @"www.baidu.com";

    //1.准备URL地址
    NSURL *url = [NSURL URLWithString:BASE_URL];

    //2.准备请求对象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    //2.1设置请求方式
    [request setHTTPMethod:@"GET"];

    //3.准备返回结果
    NSURLResponse *response = nil;
    NSError *error = nil;

    //4.创建链接对象,并发送请求,并获取结果(需要的数据)
    NSData *data =  [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

    //5.打印获取到的一些信息
    NSLog(@"结果类型:%@",response.MIMEType);
    NSLog(@"请求的网址:%@",response.URL);
    NSLog(@"结果长度:%lld",response.expectedContentLength);
    NSLog(@"请求到的结果:%@",data);

    //6.解析文件
    NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];

    //7.显示在textView里
    self.textView.text = [NSString stringWithFormat:@"%@",dict];
}

#pragma mark - get异步
- (IBAction)getAsyncButtonAction:(UIButton *)sender
{
    //1.准备url地址
    NSURL *url = [NSURL URLWithString:_BASE_URL];

    //2.创建请求对象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    //3.创建链接对象,发送请求
    [NSURLConnection connectionWithRequest:request delegate:self];

}



#pragma mark - POST同步
- (IBAction)postSyncButtonAction:(UIButton *)sender
{

    //1.准备网址
    NSURL *url = [NSURL URLWithString:_BASE_URL];

    //2.准备请求对象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    //2.1设置请求方式
    [request setHTTPMethod:@"POST"];

    

    //2.2设置请求参数
#warning 设置请求参数,需要的是NSData类型

    NSData *param = [_BASE_URL1_PARAM dataUsingEncoding:NSUTF8StringEncoding];

    [request setHTTPBody:param];

    //3.创建链接对象,并发送请求,获取结果
    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

    //4.解析
    NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];

    //5.显示
    self.textView.text = [NSString stringWithFormat:@"%@",dict];

}


#pragma mark - POST异步
- (IBAction)postAsyncButtonAction:(UIButton *)sender
{
    __block ViewController *weakSelf = self;

    //1.准备地址
    NSURL *url = [NSURL URLWithString:_BASE_URL];

    //2.创建请求对象,并设置请求方法和参数
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    [request setHTTPMethod:@"POST"];

    [request setHTTPBody:[_BASE_URL1_PARAM dataUsingEncoding:NSUTF8StringEncoding]];

    //3.创建链接对象,发送请求,在block内部完成分析
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue new]  completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

//NSLog(@"%@",data); 

        //4.解析
        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];

      //5.回到主线程,进行更新页面
        dispatch_sync(dispatch_get_main_queue(), ^{

            weakSelf.textView.text = [NSString stringWithFormat:@"%@",dict];

        });
    }];
}



#pragma mark - 清除
- (IBAction)clearButtonAction:(UIButton *)sender
{
    _textView.text = nil;

}


#pragma mark - 实现协议方法

#pragma mark 开始接收请求结果
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    //初始化
    self.mutableData = [NSMutableData data];
}


#pragma mark - 接收数据
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    //拼接接收到的数据
    [self.mutableData appendData:data];
}


#pragma makr - 接收完毕
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{

    //解析
    NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:_mutableData options:NSJSONReadingAllowFragments error:nil];
    _textView.text = [NSString stringWithFormat:@"%@",dict];

}



#pragma mark - 接收错误

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{

    
}
- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.

}

@end